😂😂😂 "It's a bug in the bug" I meant the game. I have only tried it in Chrome but some friends confirmed it was working well in Safari as well.
About the bug, I was trying to access the world array out of bounds. I was so obsessed about it being related to the clones and multiple realities management, but you hinted me in the right direction... I was trying to access an out of bounds position of the word array.
It's now fixed, using my pathfinding map that I already use for the enemies and now the fire is blocked by obstacles.